This is one tactic I found only recently:-

- Do some cross breeding to find the best breed to mass produce (ie best price ($20 - $35) and most stable health wise. (Ususally a Goldbulb or Leaffish satisfy this search)
- Sell all of your other breeds (except for your magic fish of course).
- Breed 7 of these fish to be your breeding stock.
- Keep these 7 and your magic fish in tank 1, always keeping the 7 pregnant (with each other, not the magic fish).
- When they give birth, impregnate them again and move the babies to the selling tank. USE THE SELLING TANK AS A NURSERY!!
- When the babies mature, sell them.
- keep repeating this process while you get enough funds to do research, buy the next tank etc.
- when you have got better environment, buy some of the rarer eggs, and then start experimenting with your breeding.

NOTES:- 6-7 breeding stock is the perfect number until you have the plant that gives more babies, then it's 5
- keep the babies out of the breeding tank to maximise babies.
- don't cross breed anything with your magic fish until you have better environment, otherwise they will die.
- Unless you are morally against it, kill any diseased fish. Buying cures and slowly using them is expensive and time consuming.